So far, many kinds of herbicides have been put to practical use in order to protect important crops, such as rice, soybean, wheat, corn, cotton and sugar beet from weed damage and to increase the productivity of said crops. Existing herbicides, however, do not necessarily meet the all performance to be needed.
No herbicidal effect of the compounds according to the present invention has been known at all so far, each of which compounds has a pyrimidinone ring carrying a haloalkyl group at 6-position and a substituted phenyl group at 3-position and fused with a heterocyclic ring at 1,2-positions.